Asynchronous rendering of the head tag (async)
Please note that all Sulvo ads and ad creatives are 100% async by default. This article discusses async pros and cons about the head tag only.
The reason why the publisher community has been historically so focused on async tags is because at the advent of programmatic ads there were many ad providers that blocked the page from rendering until the entire auction and creative was sent back to be loaded on the site. That is not how the Sulvo adserver renders impressions because all Sulvo ads and ad creatives are 100% asynchronous. Sulvo understands the need for a fast website to benefit both UX and revenue. We also emphasize this with our daily measurement of each site's User Experience Reports (located under "Reports--->User Experience").
If you have been experimenting with header bidding you likely know the need to minimize scripts running on a page. Sulvo understands that as well, and unlike with header bidding, Sulvo's head script is extremely lightweight.
Loading the head tag synchronously and the ad creatives asynchronously is the best way to find a balance between UX, site revenue and a fast loading page. Sulvo's head script simply pre-initializes the ad server, it does not hold the page for ads to load. The ad creatives are always loaded asynchronously to make the site as visitor friendly as possible. Since the head tag is extremely lightweight (no more than 2kb!) and is loaded immediately (through the worlds fastest CDN servers closest to your visitor's location) it does not slow the site down regardless of where your users are loading it from.
However, even with all of the above, technically it possible to load the head tag asynchronously as well but it will result in a decline in site earnings since modern browsers de-prioritize the priority of async tags. What this means is that a sync head tag that is extremely fast and lightweight (like the sulvo head tag) will be called faster by the modern browsers than any sync tag could hence async loading of the head tag is not recommended.
If you are worried about reliability, please also note that Sulvo runs on the world's most reliable and fastest network of servers that also powers over half of the entire world's DNS requests. What this means is that for the site to experience any issues, likely half of the world's entire internet infrastructure would have to experience those exact same issues too.